DVD-9

One form of DVD discs that means a single-sided dual-layer DVD disc. DVD-9 can hold approximately 7.95 gigabytes of data, even though marketers like to use the 8.5GB value instead, but this is misleading and is calculated by using so-called "Japanese gigabytes" which means that gigabyte is calculated as 1,000 megabytes, but in real computer terminology, gigabyte is 1,024 megabytes.

DVD-9 DVD-Video discs are problematic for DVD-R owners, because the cheap, writable single-layer DVDR discs can only hold the same amount of data that DVD-5 discs contain, due technical reasons. However, there are several ways to copy a DVD-9 disc to a standard, single layer DVD-R or DVD+R disc -- we have several guides available how to do this on our guide section.

DVD-9 is nowadays often used as the marketing term for dual layer DVD-R and DVD+R discs and use of that name is quite appropriate as the dual layer recordable discs can hold exactly the same amount of data as "pressed" DVD-9 discs can.

Other regular DVD size acronyms are:
-DVD-5
-DVD-10
-DVD-14
-DVD-18

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Comment this glossary entry!
Stedevil 28 April, 2007 0:19
"...7.95 gigabytes of data, even though marketers like to use the 8.5GB value instead, but this is misleading and is calculated by using so-called "Japanese gigabytes" which means that gigabyte is calculated as 1,000 megabytes, but in real computer terminology, gigabyte is 1,024 megabytes." Gosh, so much ignorance presented as facts in one place... "Japanese gigabytes" is neither a marketing trick nor is it "Japanese". It is the INTERNATIONAL STANDARD (SI Units) agreed upon and used all over the world for the last 50-100 years, except for the few places that still cling onto 18th century measuring units like inch, feet, gallons. International standard Kilo (k) = 1000 Mega (M) = 1000k Giga (G) = 1000M In REAL computer terminology (and not the nonsense above) Kibi (Ki) = 1024 Mebi (Mi) = 1024Ki Gibi (Gi) = 1024Mi So when a company writes 8,5G they are perfectly correct in doing so since 7,95GB would be INCORRECT (7,95GiB would be correct though).
darrennie 20 June, 2007 23:26
The International Electrotechnical Commission (IEC) adopted new binary prefixes in 1998, formed from the first syllable of the decimal prefix plus 'bi' (pronounced 'bee'). The symbol is the decimal symbol plus 'i'. So now, one kilobyte (1 kB) equals 1000 bytes, whereas one kibibyte (1 KiB) equals 210 = 1024 bytes. Likewise mebi (Mi; 220), gibi (Gi; 230), tebi (Ti; 240), pebi (Pi; 250), and exbi (Ei; 260).
darrennie 20 June, 2007 23:30
minor screwup 210 should read as 2 to 10th power, 220 = 2 to 20th etc.
dipwad 9 July, 2007 14:42
OK, I tried burning a DVD-9 game to a DVD+R Double Layer made by HP, and it didn't work. Is Double Layer a different type of disk than DVD-9? Perhaps swap magic can't recognize the non-pressed DVD-9?
Ethrieltd 12 August, 2007 6:35
did it work partially or not at all? if it did partially then is the layer break in the same place on the backup? If it didn`t work at all then is the disk readable "at all" or readable partially. what exactly happens when you attempt to boot the disk?
GateGod 25 August, 2007 9:25
Hi all, I have a silly questions. Is DVD9 what you have to use to back-up PS & PS2 games? I've tried to make back-ups before using regular dvds, with no success. Any good websites to learn how to do that? Thanks! GateGod :O)
dinu1980 23 February, 2008 1:24
Hi, all i need help you all. i have Sony DVD RW DW-Q120A drive but cann't play DVD-9 video disc Please guide me
folders21 24 February, 2008 11:36
hello all i have a question. on some movies that i am trying to back up i get a (data error cyclic redundancy check) message. does anyone know how i can stop that from happening or why it is happening thanks
cact25 13 April, 2008 15:43
It is copy protected in a different manner than many disks. Try using DVD Fab HD Decrypter.
aveman 30 June, 2008 20:36
what can i use to put a 7 gb game on
baedaebok 23 July, 2008 22:06
When ripping a DVD, is it better to rip it to a DVD9 or DVD5 format? I'm using DVDFab and this software lets you choose DVD5 or DVD9 format.

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